With continuous miniaturization and ever-increasing functionality of modern electronic devices, power electronic circuits, such as switched mode power supply (SMPS), or integrated voltage regulator (IVR), are required to minimize power consumption, and hence increase battery lifetime within a compact size. However, the performance advancement is often limited by the magnetically induction devices, such as inductor or transformer, which either has a poor power efficiency (leading to short battery lifetime) or occupies a large chip area (leading to bulky size). This is especially true in mobile devices, such as smartphones, tablets, digital cameras, and gaming consoles.
From an electrical circuit point of view, it may be preferred to use two phase power converter designs based on coupled-inductors compared to a single-phase buck converter type design to improve power conversion efficiency. However, use of coupled-inductors may lead to substantial increases in chip footprint area.
From the foregoing discussion, it is desirable to provide tools and techniques to develop and fabricate monolithically compact coupled-inductors with a high power conversion efficiency.